The present invention relates generally to telecommunication equipment and systems, and particularly to a method of secure message delivery from a message source to a paging device.
Paging devices are evolving into information terminals, providing more information then merely a "beep" or a telephone number to be called in response to the page. In particular, paging devices can display alpha-numeric messages bearing a variety of message types. Also, by prearrangement with a message source, meaningful information can be encoded into the form of a telephone number or given pattern of digit presentation to convey, by such prearrangement, meaningful information beyond a telephone number to be called. Security with respect to information delivered to a paging device is desirable because paging devices can receive for display and storage confidential information, e.g. bank account balance information or a variety of other information the receiver considers confidential.
Security with respect to message display and device access in a paging device has been proposed wherein the user enters a password before he paging device displays certain designated messages, or before the device exits a "lockout" mode. For example, see U.S. Pat. No. 5,146,217 issued Sep. 8, 1992 to Holmes et al and entitled SELECTIVE CALL RECEIVER HAVING CONFIDENTIAL MESSAGE READ PROTECTION. Unfortunately, such arrangement does not protect the confidentiality of messages when broadcast by radio signal to the paging device. By obtaining radio receiving and data processing equipment to comply with the broadcast protocol of a given paging system, an adversary can simply eavesdrop on the radio signal broadcast and obtain confidential information.
Paging devices are generally small, miniaturized radio receiving devices including, to the extent possible in such miniaturized devices, certain memory resources and programmable processing elements. In fact, paging devices have been successfully implemented in a wristwatch according to a highly miniaturized, highly power efficient architecture. As may be appreciated, any features added to a paging device require hardware and software resources. Such hardware and software resources, however, are not always easily incorporated into highly miniaturized electronic devices, e.g., such as in a wristwatch pager. Accordingly, any feature incorporated into a paging device desirably makes minimal use of additional hardware and software resources, or, if at all possible, makes use of pre-existing hardware and software resources.
The subject matter of the present invention addresses the problem of security in a paging system by providing a mechanism for secure message management with minimal additional use of existing hardware and software resources.